Cardiac rhythm disturbances, for instance, atrial fibrillation are a frequent occurrence. Current practice usually dictates pharmacological treatments and/or electrical shock conversion for treatment of patients. Conventional pharmacological treatment of cardiac rhythm disturbances often fails and requires electrical shock conversion. Electrical shock conversion requires a high amount of energy and maintaining the sinus rhythm using this approach has proven to be quite difficult. Moreover, conventional approaches pose additional problems for treatment of patients suffering from abnormal cardiac rhythms.
Hemodynamic instability from atrial fibrillation or failure of pharmacological treatment of atrial fibrillation mandates electric shock defibrillation. Conventional external electric defibrillation procedures typically require high electrical energy (i.e., on the order of 50-150 joules) and, as a result of the intense shock and patient discomfort associated therewith, are typically delivered after general anesthesia or deep sedation, both of which are time consuming procedures. In addition, the high amount of energy required to place a patient back into sinus rhythm requires costly drugs for sedation and can cause external skin damage and pain. Moreover, external shock defibrillation is a time consuming process requiring extra man power in the form of anesthesiologists, cardiologist, and nurses. Finally, the procedure itself is not without substantial risk; the human cost associated with external shock can include disturbing cardiac liability to the point where the patient may die. The numerous complications, disadvantages and failures associated with conventional systemic use of antiarrhythmic drugs and external electrical shock procedures has prompted many attempts to significantly improve treatment and patient care.
Moreover, there is also a significant and long-felt but yet unmet need for reducing and eliminating systemic toxicity associated with conventional, systemic drug treatment of patients suffering from cardiac rhythm disturbances. High doses of drugs typically need to be administered systemically, e.g., by the oral or intravenous delivery methods, to achieve sufficient levels within the heart tissue in order for the drug treatment to have any effect. However, these high doses of drugs are generally unacceptable due to systemic side effects. Thus, a significant need exists for treatment of patients which does not suffer whole systemic toxicity associated with systemic delivery.
Conventional treatments for chronic atrial fibrillation (AF), such as for example surgical treatments and cardiac abrasions (radiofrequecy, cryoabrasion), are often associated with grave, problematic and serious complications including, for instance, bleeding, perforations, scar-stricture and even death.
In addition, temporary treatments do not address the significant population of patients that suffer long-term from chronic cardiac rhythm disturbances. Unlike the invention described in U.S. Pat. No. 6,965,798, which is directed solely to the temporary treatment of atrial rhythm disturbances in postoperative cardiac patients, there still remains a significant, long-felt and yet unmet need for safe and effective long-term treatment of patients suffering from chronic or long-term abnormal cardiac rhythms. A significant, long-felt and yet unmet need exists for new modes of treatments for chronic atrial fibrillation. These new treatments are needed in order to improve or eliminate problems of current treatments such as systemic drug toxicity, high electric energy requirements for cardioversion and high invasiveness.